The present invention relates to a new fluorine-containing novolac resin favorably usable as a fluorine based surfactant (hereafter a term “fluorine based surfactant” refers to a fluorine based surfactant in a broad sense and includes a fluorine based surface modifying agent and the like, as well as a fluorine based surfactant in a narrow sense), a fluorine based surfactant including the above-described fluorine-containing novolac resin, a fluorine based surfactant composition including the above-described fluorine-containing novolac resin, and a resin composition including the above-described fluorine-containing novolac resin, an organic solvent, and a curable resin.
Fluorine based surfactants are primarily used as additives and have the functionality, e.g., a leveling property, wettability, penetrability, blocking resistance, water repellency and oil repellency, and soiling resistance (refer to, for example, Patent Document 1). Regarding materials including such fluorine based surfactants, if decomposition reactions occur through heating, moistening, or exposure due to chemical agents, e.g., acids or alkalis, in the following working processes or in the use of products after working, contamination of production lines due to volatilization of the decomposition products, changes in surface properties, deterioration in blocking resistance, deterioration in water repellency and oil repellency, and deterioration in soiling resistance occur.
[Patent Document 1]
Japanese Unexamined Patent Application Publication No. 02-041308